Surgical saw



Jan. 16, 1945. F. REPROGLE SURGICAL SAW Filed April 28, 1941 fflV/RfOf FRANK KEPROGLII/ ,4 orvey Patented Jan. 16, 1945 UlTED STATES PATENT I OFFICE" Application April 28, 1941, Serial No. 390,725

3 Claims.

This invention relates to improvements in saws, and more particularly to a saw adapted to slit through a surgical cast, bandage or the like previously placed on or about a body member. and has among its objects the production of a tool that will accomplish this function rapidly. easily, and painlessly, and without danger of injuring the person during the said operation.

Other objects of my invention are to so construct a tool of the kind described, that it will be neat and attractive in appearance, comparatively light in weight so as to be easily manipulated in operation, simple in construction, easily and rapidly adjustable to accommodate the varlous angles and positions for operative manipulation, and otherwise satisfactory and efficient for use wherever deemed applicable.

A further object of my invention is to so construct a cast slitting saw of the kind described, that the tool will be comfortably supported on the body member being worked on, by a guard or foot element that can enter between the latter and the cast, so that the saw periphery is just out of contact with the top surface of said foot, whereby when the tool is in operation in said position the cast will be sawed or slit almost clear down to the lowest point, and the minute thickness that may still remain will be slit or cut by a sharpened edge upwardly and rearwardly of said foot.

Many other objects and advantages of the construction herein shown and described will be obvious to those skilled in the art to which this invention appertains, as will be apparent from the disclosures herein given.

To this end, my invention consists in the novel construction, combination and arrangement of parts herein shown and set forth, and the uses mentioned, as will be more clearly pointed out in the claims hereunto appended.

In the drawing, wherein like reference characters indicate like or corresponding parts throughout the views,

Figure 1 is a side elevation of the tool as viewed from the front;

Figure 2 is a side elevation of the forward end of the same, with the saw blade removed;

Figure 3 is a cross-sectional view of the same: and

Figure 4 is a fragmentary side elevation of the tool as viewed from the rear.

Referring more particularly to the drawing, wherein I have illustrated a preferred embodiment of my invention, there is shown a tool that is especially intended for cutting or slitting longitudinally through a surgical cast, bandage or the like, and which is preferably a portable device, so that the same may be simply plugged into the nearest electric socket and is then ready for operation.

The task of removing all or a portion of a cast is a slow, tedious and many times a painful job, and is often avoided until absolutely necessary. With a tool of the kind illustrated and as about to be described, this operation may be done so rapidly, neatly and painlessly that frequent inspections of the injured body member is encouraged, and the danger of improper treatment and unnecessary permanent injury to the patient is avoided.

The tool illustrated is power-driven by a selfcontained electric motor unit I, preferably operable on either A. C. or D. C. circuit, and having the carrying handle 2 at its rear end, with a control switch 3 handily thereadjacent.

The main drive shaft 4 is operated through the motor unit, and is provided with a bevel gear 5 at its forward end, to mate with a bevel gear 6 carried by a shorter shaft 1 arranged at right angles to the first shaft. A tubular housing or sleeve 8 r is connected at its rear end to the motor housing and encloses said shafts.

It is to be particularly noted -at this point, that the free end of said shaft 1 is cut back along a pair of parallel planes longitudinally of the shaft, to form the non-circular transverse cross- I section head 8' projectin out of said sleeve 8, for a purpose about to be described.

A circular saw blade I0 is formed with a central opening H of a shape to be snugly received .by said shaft head 9, the latter projecting a short distance beyond the saw blade after the latter has been mounted thereon. This non-circular head and socket or opening, provides an efficient driving connection between the shaft and saw said section locked at any point of its rotational adjustment, I have provided a circularly extending groove or guideway M in one of the relatively movable elements, as for example in the element l2, this guideway having the pair of overhanging flanges l5|5 along either edge. A key i6 is slidable along said guideway and is shaped to be enlarged beneath said flanges, said key being carried by said housing or sleeve 8, and tightened in place with the thumb-nut I! or the like.

The other section, l3, of the saw casing is provided with fastening means l8 for holding the sections closed about the saw blade, and with a handle H! for grasping with one hand by the operator while he uses the other hand for holding the rear end of the tool, thus giving him a good control of the manipulation of the tool at all times.

A bearing element 20 is carried by the section 13, to releasably receive the projecting, noncircular end of the shaft 1, this element 20 being provided with a circular race-way so that the element 20 is properly journalled to permit rotation of said shaft while the casing is in closed position. The simple opening movement of the casing l3 carries the bearing 20 therewith to expose the head end of the shaft 1 to permit mounting or removal of the saw blade, the hub of said bearing element providing a thrust or abutment for the outermost face of the saw blade, in addition.

A guard or foot member is carried by the tool, so as to enable said foot to enter beneath the cast or bandage about to be slit for inspection or permanent removal, or for any'other desired purpose, this member having a base portion 2! of some relatively thin and sufilciently sturdy material so as to permit entry beneath the said cast or the like and support the tool therealong, and with an upwardly and rearwardly extending curved portion 22 from the rear of said base portion 2|, the forward edge 23 of said rear portion 22 being preferably sharpened, as shown, especially at its lower terminus.

The forward end of the portion 2| 0! the foot or guard member may be narrowed to permit a more ready insertion between the bandage and the body member encased thereby, and this end may be thinner than the other part to the rear of the same, if so desired and found suitable.

The base of the guard is suiiiciently wide to easily support the weight of the tool without dis-' comfort to the patient, and to insure that the saw edge will not project beyond either side 'edge of said base, and said base is positioned immediately adjacent or beneath the teeth/ or peripheral edge of the saw blade, so thatthe latter may out almost clear through the thickness of the cast or bandage, and the the sharpened edge of the trailing portion 22 of the guard will shear through the slight remaining thickness of cast or bandage.

The guard element may be construe d either integral with the casing, or may be removably secured to the same as shown. The foot will retain its fixed spacing from the saw periphery at all times, the angular adjustment of the casing on the housing 8 merely carrying the foot in the circular path about the saw blade without disturbing said spaced relationship.

Having thus described my invention, it is obvious that various immaterial modifications may be made in the same without departing from the spirit of my invention; hence I do not wish to be understood as limiting myself to the exact form, arrangement, construction and combination herein shown and described, except as limited by the state of the art to which this invention appertains, and the claims hereunto appended.

What I claim as new and desire to secure by Letters Patent is:

1. In a tool for cutting longitudinally through a surgical cast, a circular saw blade having a non-circular central shaft opening, a motor driving a journalled shaft provided with a portion non-circular in transverse cross-section to detachably receive and drivingly interlock with said blade and project beyond the latter, and a casing mounted to be rotatably adjustable about said blade and comprised of mating sections one on either side of said blade, one of said sections having a bearing to detachably receive and journal said projecting end of said shaft when the casing is closed.

2. In a tool for cutting through a surgical cast, a housing provided with a handle for control of the tool, a rotary driven blade mounted on said housing and adjustable thereon about its own center, and a guard foot fixed to said housing and rotatably adjustable therewith while mounted in place thereon for engagement beneath said cast immediately beneath the cutting portion of said blade while the latter progresses longitudinally through the cast, said foot being maintained in fixed spaced relation to the periphery of said blade at all points of its rotary adjustment.

3. In a tool for cutting through a surgical cast on a body member, a circular blade having a central opening, a driving shaft provided with a circular cross-sectional portion to act as a journal and with an end shaped to detachably .and drivingly receive said blade and project axially beyond the latter, means on said shaft and On said blade providing a driving connection therebetween, a casing mounted about said blade and comprising two mating sections one on either side of said blade, one of said sections being movable to open or close the casing, and a bearing provided in said movable section to detachably receive said projecting end of said shaft while the casing is closed.

FRANK REPROGLE. 

